1. Technical Field
The disclosure generally relates to lighting sources, particularly, to a backlight module with light-guiding portions.
2. Description of Related Art
A typical backlight module includes a substrate, a plurality of light emitting diode (LED) packages arranged on the substrate, and a light diffusion board spaced and over the LED packages. The light diffusion board includes a flat light incident surface facing toward the LED packages and a flat light output surface opposite to the flat incident surface. Light emitted from the LED packages emits into the light diffusion board from the flat incident surface of the diffusion board, and then, the light can be diffused by the light diffusion board to emit out from the flat light output surface.
However, each LED package generates a smooth round light field, and the light emitted from the LED package is mainly concentrated at a center thereof. The light at a periphery of the LED package is relatively poor to illuminate. Therefore, the light emitted from the LED packages can not be uniformly emitted into the light diffusion board. When this happens, the performance of the backlight module deteriorates. Particularly, the LED packages are made to be more and more powerful. If the light diffusion board and the LED packages are located too close to each other, white spot mura may appear in the LCD which is lightened by the backlight module. If the distance between the light diffusion board and the LED packages is increased, a bulk of the backlight module must be increased accordingly, which is opposite the trend of compact design.
What is needed, therefore, is a backlight module with light-guiding portions which can overcome the described-above shortcomings.